Crossover Study of Zafirlukast in Preventing Allergen-induced Signs and Symptoms in Response to Cat Dander Challenge

Exclusion Criteria

• •Receiving immunotherapy for cat allergy
• •Predictable seasonal allergy during the study period
• •Newly (\< 2 weeks) diagnosed with Corona Virus Disease (COVID-19)
• •Regular use of controller medication for moderate to severe asthma
• •Subject works with cats or keeps a cat as a pet.
• •Inability or unwillingness to give written informed consent.
• •History of upper/lower respiratory tract infection, requiring systemic steroids, antibiotics, and or emergency room (ER) visit or urgent care within 6 weeks of screening visit.
• •History of adverse reaction or allergy to Zafirlukast
• •History of neurological, hepatic, renal, diabetic mellitus, thyroid disorder, psychiatric, addiction or other medical conditions that may interfere with the interpretation of data or the patient's participation in the study or may increase safety concerns per investigator discretion.
• •History of cardiovascular diseases including uncontrolled hypertension (blood pressure \>160/100 mmHg), ischemic heart disease, congestive heart failure (New York Heart Association III or IV), valvular heart disease or cardiomyopathy (e.g., depressed left ventricular ejection fraction by echo, arrhythmias).
• •Known allergy or sensitivity to atropine or ipratropium bromide.
• •Documented or self-reported current history of alcoholism or drug abuse.
• •Baseline Spirometry Forced Expiratory Volume in first second (FEV1) \<70% of predicted
• •Participated in another research trial and received investigational drug within 30 days or 5 half-lives, whichever is longer
• •Unwillingness or inability to comply with study procedures.